Ultrasonic diagnostic imaging system with assisted border tracing

Abstract

A method and system for tracing a tissue border in a medical diagnostic image are described in which a diagnostic image containing the tissue to be traced is acquired. A user manipulates a cursor on the image display to designate three landmarks on the boundary of the tissue. An automated border detector then fits a stored boundary shape to the three landmarks. The fitted border can thereafter be adjusted to precisely fit the boundary by a rubberbanding process. In an illustrated embodiment the myocardium is traced in an image of the left ventricle by first clicking on the mitral valve corners and the apex, then fitting an endocardial border to these three landmarks, then clicking on the apex of the epicardium, then fitting an epicardial border to the epicardial apex and the mitral valve corners.

1 . A method of delineating the boundary of tissue or structure in a medical diagnostic image comprising: 
 acquiring an image containing tissue or structure which is to be delineated;    manually marking at least three points of the boundary which is to be delineated; and    automatically fitting a predetermined border shape to the three points of the boundary, whereby the fitted border shape indicates a boundary of the tissue or structure in the image.    
   
   
       2 . The method of  claim 1 , wherein manually marking and automatically fitting further comprise: 
 manually marking two points of the boundary;    manipulating a cursor to move to a third point of the boundary; and    automatically fitting the predetermined border shape to the two marked points and the cursor as the cursor is moved to the third point.    
   
   
       3 . The method of  claim 1 , further comprising: 
 automatically aligning the fitted predetermined border shape to the boundary of the tissue or structure in the image.    
   
   
       4 . The method of  claim 1 , further comprising: 
 manually marking at least one point of a second boundary which is to be delineated; and    automatically fitting a predetermined border shape to the point of the second boundary and at least one point of the points of the first-named boundary.    
   
   
       5 . The method of  claim 4 , wherein automatically fitting a predetermined border shape to the point of the second boundary comprises automatically fitting a second predetermined border shape to the point of the second boundary and two of the points of the first boundary.  
   
   
       6 . The method of  claim 1 , further comprising: 
 manually adjusting the fitted border shape to align with the boundary of the tissue or structure in the image.    
   
   
       7 . The method of  claim 6 , wherein the act of manually adjusting the fitted border shape comprises adjusting the fitted border shape by a rubberbanding adjustment.  
   
   
       8 . The method of  claim 1 , wherein acquiring further comprises acquiring an ultrasonic image of the heart; and 
 wherein manually marking further comprises manually marking at least three points of a wall of the heart in the image,    wherein the fitted border shape indicates the heart wall in the image.    
   
   
       9 . A method of delineating the myocardium in a cardiac image comprising: 
 acquiring a diagnostic image of the heart including the myocardium;    manually marking at least three points of the endocardium; and    automatically fitting a predetermined endocardial border shape to the three points of the endocardium, whereby the fitted border shape indicates a boundary of the myocardium.    
   
   
       10 . The method of  claim 9 , further comprising selecting one of a plurality of predetermined endocardial border shapes to be fitted to the three points of the endocardium.  
   
   
       11 . The method of  claim 9 , wherein acquiring further comprises acquiring an echocardiographic image of the left ventricle; 
 wherein manually marking further comprises manually marking three landmarks on the endocardium in the image of the left ventricle; and    wherein automatically fitting further comprises automatically fitting a predetermined left ventricle endocardial border shape to the three landmarks.    
   
   
       12 . The method of  claim 11 , wherein manually marking three landmarks further comprises marking the MMA, the LMA and the apex of the left ventricle in the image.  
   
   
       13 . The method of  claim 9 , further comprising manually marking a point of the epicardium; and 
 automatically fitting a predetermined epicardial border shape to the point of the epicardium and at least one point of the endocardium.    
   
   
       14 . An ultrasonic diagnostic imaging system for delineating an anatomical boundary in an image comprising: 
 a scanhead having an array transducer for scanning a region of interest;    a beamformer coupled to the array transducer which acts to beamform echo signals received from the region of interest;    an image processor coupled to the beamformer which acts to form an image of the region of interest;    a user operated pointing device which enables a user to manipulate a cursor in the image and to identify at least three points on an anatomical boundary in the image;    a source of border shapes; and    an assisted border detector, coupled to the source of border shapes and responsive to the image processor and the pointing device which acts to fit the border shapes to the points identified by the user operated pointing device.    
   
   
       15 . The ultrasonic diagnostic imaging system of  claim 14  further comprising: 
 a graphics processor, responsive to the border shape fitted by the assisted border detector, which acts to produce a graphic overlay including the fitted border shape; and    an image display responsive to the image processor and the graphics processor for producing an image of the region of interest with a delineated boundary.    
   
   
       16 . The ultrasonic diagnostic imaging system of  claim 15 , further comprising a selector, coupled to the source of border shapes, which enables selection of one of the border shapes for use by the assisted border detector.  
   
   
       17 . The ultrasonic diagnostic imaging system of  claim 14 , wherein the scanhead further comprises a scanhead having an array transducer for scanning a volumetric region of interest.